1. Field of the Invention
The present invention relates to elastomer-coated bias fabrics of the type employed as reinforcement in such industrial products as power transmission belts, hoses, tires and the like and, more particularly, to neoprene-coated bias-cut reinforcement fabrics having at least one tacky surface; and to a method for producing the same.
2. Prior Art Statement
Bias-cut fabrics which have previously been coated and impregnated with an uncured, tacky, elastomeric compound, such as a synthetic elastomer, have conventionally been used in the production of power transmission belts, hoses, and the like as a protective cover and reinforcement. It is the common practice to combine the pre-coated bias-cut fabric with the carcass, substrate, or core of the product during the vulcanizing operation, such that heating cures and bonds the fabric to the rubber base of the product.
Elastomer-coated bias-cut fabrics have been the subject of a number of U.S. Patents including:
U.S. Pat. No. 1,323,212 (1919) to Bulley PA1 U.S. Pat. No. 3,784,427 (1974) to Griffin PA1 U.S. Pat. No. 3,832,210 (1974) to Rohlfing PA1 U.S. Pat. No. 4,283,455 (1981) to McGee as well as the following U.S. Patents to the present inventor: PA1 U.S. Pat. No. 4,062,989 (1977) to Long PA1 U.S. Pat. No. 4,116,159 (1978) to Long PA1 U.S. Pat. No. 4,205,559 (1980) to Long et al PA1 a bias fabric having opposed surfaces, yarns or fiber bundles, and interstices between said yarns or fiber bundles, PA1 a layer of an uncured elastomeric composition coated on both surfaces of said fabric and penetrating said yarns or fiber bundles and said interstices, PA1 a tackifying agent present in one of said layers of said uncured elastomeric composition or in a separate layer of an uncured elastomeric composition overlying one of said layers on one surface of said fabric wherein the improvement resides in incorporating said tackifying agent in a composition of a non-carboxylated elastomer.
Bulley discloses a rubber impregnated bias cut fabric for use in a tire carcass.
Griffin discloses a method and apparatus for manufacturing an elastomer-coated bias cut fabric wherein a tubular woven fabric is cut spirally at a 45.degree. angle to produce a continuous sheet of fabric which is impregnated with a curable binder and transversely stretched on a tenter frame to increase the complementary angle of the warp and weft threads. The binder is cured or otherwise hardened to stabilize the fabric and is subsequently immersion impregnated with an elastomeric composition, such as neoprene dissolved in a solvent, dried, and cut into strips for application to V-belt cores.
McGee discloses a process which parallels that of Griffin wherein the fibers of the fabric are immersed in an elastomeric composition containing a pigment and then coated with another layer of elastomer. The pigment is removed as the edges of the fabric are abraded to reveal the white threads of the fabric which can then be interpretted as a sign of wear.
Rohlfing discloses a bias cut fabric which is manufactured from a tubular fabric woven such that when the fabric is cut on the 45.degree. bias there is a minimum of selvage.
Long '989 discloses a method and apparatus for uniformly coating and impregnating a bias-cut woven fabric with a tacky elastomer. The fabric is coated while the fabric is pantographed on a tenter frame by sequentially applying a viscous elastomeric coating to the lower and upper surfaces of the fabric inwardly of the edges and by smoothing the coatings to a uniform thickness.
Long '559 is directed to a neoprene coating composition useful in the Long '989 process wherein a carboxylated neoprene is tackified with a high boiling aromatic oil.
Long '159 is directed to a coating head for applying viscous coating such as elastomeric latices to a moving woven web. The coating head employs a pair of elongate manifolds extending across the web which simultaneously coat both surfaces of web by extrusion and thereby ensure penetration of the interstices of the fabric by the coating composition.